Resetting mechanism for indicators



Dec. .30, 1947- J. E. BEVINS 2,433,541

' RESETTING MECHANISM FOR INDICATORS j Filed June 12, 1945 4 Sheets-Sheet 1 o "f E! 0 I 0 m I I I j l l l i JaniesE Bevilzs ma 9M4.

TORNEY I Dec. 30, 1947. J, E. BEVINS RESETTING MECHANISM FOR INDICATORS Fild June 12, 1945 4 Sheets-Sheet 2 I Unvenior,

JazmE'. Bevinps.

. AT ORNEY Dec. 30, 1947. J BEVINS RESETTING MECHANISM FOR INDICATORS 4 Sheets-Sheet 3 Filed June 12, 1945 a E m Tnvenior AT ENE Y Deg. 30, 1947. v J. E.'BEV|NS I RESETTING MECHANISM FOR INDICATQRS Q Filed June 12, 1945 4 Shets-Sheet 4 Unveni'oi.

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A TTOIRNEY Patented Dec. 30, 1947 RESETTING MECHANISM FOR INDICATORS James E. Bevins, Ramsey, N. J., assignor to Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware Original application May 19, 1943, Serial No.

487,673, now Patent No. 2,394,974, dated February 19, 1946. Divided and this application June 12,1945, Serial No. 599,001

This invention relates to resetting mechanisms, and more particularly to a resetting mechanism for an instrument such as an accelerometer, hav ing a plurality of cletainable maximum indicator hands or pointers.

This application is a division'of my copending application for an accelerometerbearing Serial No; 437,673, and filed on May 19, 1943 ;-now Patent of the character described which shall be easy to-operate, relatively inexpensive to manufacture, positive in action, which shall have a large variety "of applications, and yetbe practical and efficient to a high degree in use.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists in features of construction, combinations of elements, and

arrangement of parts which will be exemplified in the construction hereinafter described, and of which the scope ofthis application willbe indicated in the appended claims.

In the drawings wherein like reference characters refer to like parts throughout the several views:

Figure 1 is a front elevation view of the assembled device. t -Figure 2 is a side elevation view partly in sec- Figure 3 is a front elevation View of the frame without the casing.

Figure 4 is a side elevation view partly in cross section.

Figure5 is a rear elevation view of the frame.

Figure 6 is an elevation view with a fragment of the main spring in cross section.

Figure '7 is an enlarged section view of the device taken along the axis of the main drive shaft.

Figures isan exploded view of the indicator .hand assemblies and their respective reset mechanisms.

Figure 9 is a detached view of the reset mechanism partly in elevation and cross section.

Referring to the drawings, in detail, in the Claims. (Cl. 116-129) illustrated embodiment of the invention, the de vice comprises a casing l l a frame Which may be cast or otherwise formed so as to have a fiat plate member [2 from which extends a plurality of lugs, as l3, I l, l5 adapted to secure the frame to the casing, and a slotted lug 16 for the purpose hereinafter described. Two flat outer frame bars i1 and-l8 continue from each end of plate i2 substantially perpendicular with respect thereto. The bars ii and I8 are provided with arcuate outer surfaces to facilitate a complementary fit within the casing H, shown in Fig. 2. The plate top bar ll of the frame contains an elongated opening 19 angularly disposed towards the rear edge of the bar for a purpose hereinafter set forth.

Extending between bars I! and I8 in spaced parallel relation to plate I2 is a fiat bar 28. Plate l2 and bar 2!) are provided intermediate their ends with axially aligned bearing openings adapted to receive and house bearing members 2| and 22, if desired of ball bearing type, associated with a main driven shaft 23 disposed in the frame parallel to outer frame bars I 1 and I8.

The driven shaft 23 is secured against axial thrust by mounting bearing 2! in the bearing opening of plate l2 against annular shoulder 24 and locking the same therein by corrugated washer 25 and split ring 26 adapted to snap into an annular groove in the bore of the bearing, opening. The corrugations of washer 25 permit slight axial resiliency, but prohibit any definite axial thrust or movement.

The main driven shaft 23 extends through to the outside flat face of plate l2 and bar 20. vThe extremity of shaft 23 outside of plate l2 carries an improved pointer or indicator mounting andoperating assembly, while the other extremity of the shaft has mounted thereon a drum pulley 21, by any suitable means such as a key 29, in Figure 7.

Specifically referring to Figures 4, '7 and 8, the improved indicator assembly, shaft 23, as it projects from the plate l2, carries a lever. 29, splined or otherwise secured, adapted to revolve in either a clockwise or counterclockwise direction to selectively operate the maximum indicator members 30 and 3| through their associated parts. The associated parts for each maximum indicator member coacting with the lever 29 are identical in construction and detailed referencev to one set of parts therefore will describe both. Accordingly, leading up to such detailed reference, the shaft 23 has a reduced shaft or extremity 32 continuing from lever 29 to the exposed tip endof which is keyed, or otherwise secured, an instantaneous inca or hand 33. Freely mounted around reduced shaft 32 is a tubular shaft or elongated sleeve 34, to the exposed tip end of which is keyed or otherwise secured a maximum indicator hand 38. Tubular shaft 34 has an enlarged stepped annular end adjacent lever 29, so as to provide annular surfaces 35, 36 and 31. The annular surface 31 is provided with an anchoring shoulder 38.

Each of the annular surfaces supports a coop crating part. Elongated annular surface 35 has freely mounted thereon an identically formed tubular shaft 39 of less length than surface 35, so as to expose the end p rtion of the shaft 34. Surface 35 is associated with a split collar 4!), keyed or otherwise secured thereto, collar 45 holding the inner coiled end of winding spring. Surface 31 is associated with. ratchet wheel or disk 42 in mesh with a pawl 43 and carries a pin or arm 44 near its peripheral edge adapted to be acted upon by lever 29.

Also, in the arc of travel of pin 44 is positioned a stop 45 adapted to prevent rotation of disk 42 beyond a predetermined point.

The spring 4| has its outer coil end anchored in forward projecting split stud 48 mounted on plate l2, so that clockwise rotation transmitted from ratchet wheel 42 winds the spring 4| about split collar 40.

The tubular shaft 39 is provided with similar annular surfaces 35A, 36A and 31A, described in connection with shaft 34, and each annular surface carries a similar corresponding part, as indicated by numerals 40a, 4m, and 42a, in Figure 8. L-shaped pin 44a is adapted to coact similarly to pin 44 with lever 29, but to permit such coaction is made longer and shaped to contact the opposite edge of lever 29.

Extending forwardly from plate I2 are spacer lugs 41 and 48 to which is secured a flat bar 58 and indicating dial 49 traversed by the indicator members 30, 3| and 33 and marked to provide readings in gs (units of gravity) of the positive or negative accelerations being applied along the vertical axis of the airplane carrying the device. The dial 49 has a centrally disposed opening in alignment with a relatively large opening in bar 50 having a bushing 50a secured therein, through which project the ends of the indicator hand shafts previously described. Obviously, the indicator hands are thus in position to turn around the dial to various readings in gs.

Secured between plate l2 and bar 20 to main driven shaft 23 at the inner coil end by a sleeve secured on the shaft is a coil spring 52 and secured at the outer end of the coil by a bolt and split sleeve fastener 53, secured within the elongated slot of lug IE. Spring 52 is so set as to retain the indicator hands and weight normally in a neutral or inoperative position. Lateral displacement of the spring coils is limited by block 55 secured to plate |2 adjacent the peripheral edges of the coils.

Above and below drum pulley 27 and angularly disposed from bar 20 at its point of junction with top and bottom frame bars I1 and i8 are lugs 53 and 51, in each of which are respectivel secured pu ley axles or shafts 58 and 59.

Pulleys 60 and 6|,which may be ball bearing type, are freely mounted on the shafts 58 and 59 for rotation, pulley 55 being visible through angular slot l9 in top bar said slot being sufficiently large to permit shaft 58 and pulley 63 to laterally move into alignment with the slot for adjustment of cable 62 on the pulley upon release of set screw 63. The axes of shafts 58 and 58 are angularly disposed with respect to the p an of the axis of the main shaft 23, that carries drum pulle 21 to prevent tangle or slack caused by overlapping cable and provide for a straight non-shearing pull and even coiling of cable 82 around the drum surface of pulley 21.

In the outer end of each bar I1 and I8, secured by set screws 64 and 55, are parallel guide rods 66 and 61, preferably spaced farther apart than the overall diameter of pulley 2! and outer peripheral edges of the pulleys 60 and 6|. The proportional spacing of guide rods 56 and 61 with respect to the foregoing elements is important for the proper installation of a mass or Weight 68.

The mass or weight 68 is designed to be of maximum avoirdupois for a minimum amount of cubic space. To provide for this the mass is cast or cut out at the side adjacent the cable pulleys in a V-shaped well portion 69 so shaped and so proportioned, as to clear the Pu eys 1, 6B and 6| during operation.

Centrally disposed and projecting through the mass or weight 68 to the vertex of Well 59 is a bushing 70 through which driving cable 82 is threaded, strung across weight 68 and secured under plate 7 suitably held in place as by screws or bolts 12 and 13 to tether the cable to the weight or mass.

The bushing 10 is held in place by set screw I4. Also, adjustably positioned in each top edge of weight 68 are stop members, such as screws or bolts 15 and 18 adapted to limit upward thrust of the weight by contact with top bar During operation of the present device the instant hand 33 moves in either direction and returns to neutral or zero position promptly in response to the tension of spring 52 when accelerated vertical impulses cease, but the maximum hands 39 and 3| as they turn in their respective fields wind springs 4| and 4| a and are locked in their furthermost positions by their respective pawl and ratchet mechanisms. Hand 39 being locked by spring pressed pawl 43 engaging ratchet wheel 42 and hand 3| being locked in the same manner by reversely rotating ratchet wheel 42a and spring pressed pawl 43a, whereupon after a specific series of indications are finished the hands 30 and 3| must be released or reset to normal position for the next dive and pull-out.

An arrangement accordingly is provided to simultaneously release both novelly mounted pawls 43 and 43a from the teeth of the ratchet wheels to reset the hands. Referring to Figures 1, 3, and 9 the reset or release mechanism comprises a knob 11, a chamber 18 in an enlarged off-set portion '19 in bezel and a shaft 8| projecting through bezel 80 and chamber 18. Bezel 80 is secured to casing II in any suitable manner, so that enlarged part 19 lines up with an inwardly extending portion of flange of casing through which extends shaft 8|. The shaft 8| has a lug 82 pointing towards the front of the casing secured thereon and normally held inoperative against the wall of chamber I8 by a spring 83. Shaft 8| at this point projects through the flange of casing ll, so that lug 82 extends into the casing between dial 49 and plate l2. Adjacent and within the radial throw of lug 82 is a bell-crank lever with arms 84 and 85 depending from a spring anchor plate 86, which plate is journaled to plate l2 by suitable means, as bolt'8'l, and a split collar 88 to hold the inner coil end of spring 89 and pawl 43.

Operation In reference to one feature of operation it should be noted that the maximum indicator hands-in the present disclosure are directly operated by the lever 29 through a'pin 44 carried-by one hand operatingzratchet disk iZ adaptedto rest against one edge of the lever and through an L-shaped pin 44a carried by another maximum hand operating disk Ma adapted to rest against the opposite edge of lever 29.

Spring 89 has its outer 'coil end anchored to plate 88 and its inner coil end anchored to split collar .88, that carries pawl43, on bolt '87, so as to normally press the pawl into engagement with ratchet wheel 42. As the ratchet wheel 42 ro tates, spring 4| winds up ontshaft 35.

Arm 84 is in the line of travel of lever 82 and arm 85 extends across plate i2 into contact with; 1 an arm Bil depending from twin spring anchor plate 86a mounted on bolt 87a, which is slightly longer than bolt 81. Split collar tea, pawl43a and spring 89a are securedtoith'e plate 85a in the same manner described as "in plate 86.

When the pilot puts;the plane in which th instrument is mounted intoa dive, the weight 68 is acted upon by positive vertical accelerations, so that cable '62 is pulled. about pulleys Bil, Bland 21, whereupon main shaft 23 is rotated in a clock- I wise direction and instantaneous indicator hand 33' carried by reduced'shaft 32 is moved to give constant positive readings in units of gravity, Directly following-actuation of the instant 'indicator hand-motion is transmitted through pin climb, whereupon the weight 68 moves along guides 66 and 61 in the opposite direction for negative indication, the chain of operation being identical to that ,just described with the exception that lever 29 moves ratchet disk 42a through L- shapedpin 44a in a reverse direction, so as to actuate maximum hand 3! in a constantly forward counter-clockwisedirection, until the. pilot levels off.

To reset the maximum indicator hands 39 and 3!, knob T! isrotated, shaft 84 rotates against spring 83 and lever 82 strikes arm 84 and rotates plate 86 against action of spring '89 and releases pawl'dfl. Simultaneously with this operation arm 85 lifts arm 98' and similarly releases pawl 43a and the maximum hands return to zero under unwinding action of springs lla and fill.

In Figure 2, is illustrated a weight holder comprising a-fiat spring 9| having its lower end 'bifurcated and secured to the back of casing H by stud 93, adapted to normally bein a retracted position against the casing wall. The-spring 9i is provided at the top with an enlarged claw head 9d anda'plurality of lugs-'95 adapted to engage around th weight when the spring is forced forward by a set screw 92 passing through the casing I l and the stud 93to hold the weight for shipping the device.

To illustrate an advantage of this device, when 'a dive approaches some predetermined value, the .pilot knows itis time-to-pull out, as during pullout a gravitational force of from 1 to 12 times rnormalmust be overcome.

:.The duration 1 of: the: acceleration issgenerally -so small'th'atiit would he'impossible forfth'e pilot ,tion.

to read the instrument: tduring'this maneuver and :therefore he must read the maximumrand mini- :mum handsafter the maneuverhas been completed. ..By associating his sensations and actions and readings "of airspeed and altitude "duringthe dive with'the accelerometer reading when the dive is completed,:the pilot can predict and contro'lthe l0- acceleration imposed .on the aircraft.

Such terrific force'increasanot only acts upon th plane and crew, but also upon the instruments in the planeandthe elimination of prior art damper-structures employing gears andlinkages, that break under such extreme gravitational force is a particularly valuable feature. of: the present invention.

There is thus provided a novel improved and simplified single means for resetting. one or more indicator hands or pointers of accelerometers havin maximum negative and positive indicator hands or pointers independently responsive to vertical accelerations of an aircraft in diving and climbing, or a dive and pull out, which may: be easily and quickly reset manually and simultaneously fromythe outside of the casing, after indicating 'or'recording such maximum'accelerations, so as to'efiect the return of such hands to zero in connection with mechanism. within the casing of the instrument, for reuse.

'While only one embodiment of the invention has been illustrated and described, various changes and'modifications, which will now appear to those skilledin the art, may be made without departing from the scope of the inven- Reference is therefore to be had to the appended claims for a definition of the limits of the invention.

What is claimed is: '1. In combination with a suitable indicator casing, a reset mechanism for indicator hands 1 comprising a manually operated actuator means,

a lever on said actuator means adapted to swing in a predetermined are, a frame in said casing-a plate journaled to said frame,.a bell-crank lever associated with said plate having an arm thereof in the line of travel of said first lever, a springpressed pawl associated with said plate adapted to engage a ratchet wheel associated with one 'of said indicator hands, a second similarly mounted plate spaced from said first plate, a spring- ;pressed pawl associated with said second plate, and a lever depending from the second plate adapted to coact with the other arm of said bell-crank lever, whereby operation of said actuator means swings the lever thereon into engagement with the bell-crank lever on the first plate and swings the bell-crank into contact with the lever dependingfrom saidsecond plate to thereby simultaneouslyrelease said pawls.

2. Means adapted to simultaneously reseta plurality of indicator pointersx'in combination with a suitable casing and a frame therein, comprising manualactuating means outside the casing adapted to extend to operativeposition within the-casing, a pair of spaced'plate members 'swivelly mounted'in the frame, a spring locked pawl mounted on each plate," a bell-crank lever associated with one of said plates and said actuindicator pointers.

3. In combination with a' suitable indicator casing having a plurality of indicator hands, a resetting mechanism comprising a manually operated actuator means, a lever on said actuator means adapted to swing in a predetermined are,

a lever in the line of travel of said first lever, releasable holding means associated with each of said indicator hands, a third lever adapted to rotate with the second lever, and a fourth lever associated with said holding means, the operation of the actuator means swings the lever thereon into engagement with the second lever to swing the third lever into engagement with the fourth lever to thereby simultaneously release said holding means.

4. A reset mechanism for indicator hands comprising a manually operated actuator means, a lever on said actuator means adapted to swing in an are, a bell-crank lever having an arm thereof in the line of travel of said first lever, releasable holding means associated with the bell-crank lever and each of the indicator hands, and a third lever adapted to coact with the other arm of said bell-crank lever, whereby actuation of the actuator means swings the lever thereon into en gagement with the bell-crank lever and swings the latter lever into engagement with the third lever to thereby simultaneously release said holding means.

5. A reset mechanism for indicator hands comprising a manually operated actuator means, a lever on said actuator means adapted to swing in an are, a bell-crank lever havin an arm thereof in the line of travel of said first lever, releasable holding means associated with the bell-crank lever and each of the indicator hands, a third lever adapted to coact with the other arm of said bellcrank lever, whereby actuation of the actuator means swings the lever thereon into engagement with the bell-crank lever and swings the bellcrank lever into engagement wth the third lever to thereby simultaneously release said holding means, and means to return said hands to normal positions upon release of the holding means.

6. A reset mechanism for indicator hands com prising the combination with a casing, actuator means, a lever on said actuator means rotatable thereby, a frame in the casing, a bell-crank lever journaled in the frame and havin an arm thereof in the line of travel of the first lever, spring-pressed holding means associated with the bell-crank lever and each of the indicator hands, a lever having a spring-pressed holding means associated therewith and adapted to coact with the other arm of said bell-crank lever whereby operation of the actuator means swings the lever thereon into engagement with the bell-crank lever and swings the bell-crank lever into engagement with the third lever to thereby release said holding means, and spring means normally holding the hands in zero position and operable upon release of the holding means.

7. A reset mechanism for indicator hands comprising actuator means, a lever on said actuator means adapted to swing in a predetermined are,

a casing, a frame in the casing, a plate journaled in the frame, a bell-crank lever associated with said plate and having an arm thereof in the line of travel of said first lever, spring means normally holding the indicator hands in zero positions, a spring-pressed holding means associated with the plate and one of the indicator hands, a second similarly mounted plate spaced from the first plate, a spring-pressed holdin means assoelated with the second plate, and a'lever extending from the second plate adapted to coact with the other arm of said bell-crank lever whereby operation of said actuator means swings the lever thereon into engagement with the bell-crank lever associated with the first plate and into contact with the lever extending from the second plate to simultaneously release said springpressed holding means.

8. Means adapted to simultaneously reset a plurality of indicator hands normally held at zero, comprising the combination with a casing and a frame therein, actuating means outside the casing extending into the casing in operative position, a pair of spaced members mounted to swivel in the frame, spring holding means on each member, a lever associated with one of said members and said actuating means, and a lever ex-- tending from the other member and over an arm on the first lever whereby movement of said actuating means rocks the first lever and moves said second lever to simultaneously release said spring holding means whereby the indicator hands return to zero.

9. A reset mechanism comprising, two movable members, and biasing means for each of said members for returning said members to their respective initial positions, a detent for each of said members to hold said members in their furthermost positions to which they are moved, a movable reset member, a third member adapted to be moved upon movement of said reset member to release one of said detents, and a fourth member adapted to be moved by movement of said third member to release the other of said detents, the release of said detents permitting said biasing means to return said first and second members to their respective initial positions.

10. A reset mechanism comprising, two movable members, and biasing means for each of said members for returning said members to their respective initial positions, a detent for each of said members to hold said members in their furthermost positions to which they are moved, a movable reset member, a third member adapted to be moved upon movement of said reset member to release one of said detents, a fourth member adapted to be moved by movement of said third member to release the other of said detents, the release of said detents permitting said biasing means to return said first and second members to their respective initial positions, and biasing means for said reset member, said third member and said fourth member to return their respective members to an initial position upon release of said reset member.

11. A reset mechanism comprising, two rotatable members, and biasing means for each of said members for returning said members to their initial positions, a spring biased detent for each of said members to hold said members in their rotated positions, a rotatable reset member, a third rotatable member adapted to be rotated by the rotation of said reset member to release one of said detents, and a fourth rotatable member adapted to be rotated by the rotation of said third rotatable member to release the other of said detents, the release of said detents permitting said biasing means to return said first and second members to their respective initial positions,

12. A reset mechanism comprising, two rotatable members, and biasing means for each of said members for returning said members to their initial positions, a spring biased detent for each of said members to hold said members in their rotated positions, a rotatable reset member, a third rotatable member adapted to be rotated by the rotation of said reset member to release one of said detents, a fourth rotatable member adapted to be rotated by the rotation of said third rotatable member to release the other of said detents, the release of said detents permitting said biasing means to return said first and second members to their respective initial positions, and resilient means for said reset member, said third member and said fourth member for returning said members to their initial positions upon release of said reset member.

13. A reset mechanism comprising, two rotatable members adapted to be rotated in opposite directions, biasing means for each of said rotatable members for returning their respective members to an initial position, a spring biased detent for each of said members biased in a direction opposite to that in which its associated member is rotated to hold said members in their rotated positions, a reset member adapted to be rotated, a third member adapted to be rotated by the rotation of said reset member in a direction which is opposite to the bias of one of said detents to release said detent, and a fourth rotatable member adapted to be rotated by the rotation of said third member in a direction opposite to said third member to release the other of said detents, the release of said detents permitting said biasing means to return said first and second members to their respective initial positions.

14. A reset mechanism comprising, two rotatable members adapted to be rotated in opposite directions, biasing means for each of said rotatable members for returning their respective members to an initial position, a spring biased detent for each of said members biased in a direction opposite to that in which its associated member is rotated to hold said members in their rotated positions, a reset member adapted to be rotated, a third member adapted to be rotated by the rotation of said reset member in a direction which is opposite to the bias of one of said detents to release said detent, a fourth rotatable member adapted to be rotated by the rotation of said third member in a direction opposite to said third member to release the other of said detents, the release of said detents permitting said biasing means to return said first and second members to their respective initial positions, and resilient means for said reset member, said third member and said fourth member for returning said members to their initial positions upon release of said reset member.

15. A reset mechanism comprising, two coaxial shafts rotatable in directions opposite to each other, a return spring for each of said shafts, a detent for each of said shafts to hold said shafts in the positions to which they are rotated, a manually operable reset member, and means rotatable upon actuation of said reset member to release both of said detents to permit the simultaneous return of both of said coaxial shafts under the influence of their respective return springs to their initial positions.

JAMES E. BEVINS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,262,008 Kollsman Nov. 11, 1941 2,110,391 Davis Mar. 8, 1938 846,376 Adams Mar. 5, 1907 826,198 Snyder July 17, 1906 972,144 Allen Oct. 11, 1910 

